Mi madre es muy (1) (trabajador / rubio): es artista y también enseña en una universidad. a los estudiantes les gusta mi madre porque es una profesora (2) (bueno / antipático), pero ella da (gives) exámenes muy (3) (bonito / difícil). este semestre enseña dos clases de arte (4) (delgado / chino). mi madre es una (5) (grande / mismo) mujer, ¿verdad?

1. Mi madre es muy trabajadora: es artista y tambien ensena en una universidad.
This sentence means - My mother is very hard-working: she is an artist and she also teaches at a university. Here you have to use the word trabajadora (diligent, hard-working), instead of rubia (which means blonde). Also, since mother is a female, you need to change the form from trabajador to trabajadora, which is female.

2. A los estudiantes les gusta mi madre porque es una profesora buena. 
This sentence means - Students like my mother because she is a good professor. Here, you have to use the word buena (which means good), instead of antipatica (which means unpleasant). Also, since it is a woman, you have to change the gender from bueno to buena.

3. ... pero ella da examenes muy dificiles.
This part of the sentence means - ... but she gives very difficult exams.Here you have to use dificil (hard, difficult) instead of bonito (which means pretty). Also, since examenes is plural masculine, you have to change the word dificil (which is singular masculine) into dificiles.

4. Este semestre ensena dos clases de arte chino.
This sentence means - This semester she teaches two classes in Chinese art. You have to use the word chino (which means Chinese) instead of delgado (which means pleasant). Also, since the word arte is masculine (only in the singular form; if it's plural, then it becomes feminine - las artes), the form of the word stays the same - chino.

5. Mi madre es una grande mujer, verdad?
This sentence means - My mother is an amazing woman, isn't she? Here you have to  use the word grande (which means great, amazing) instead of mismo (which means 'the same'). Also, the adjective grande stays the same for both feminine and masculine form, so you don't have to change anything here.

The correct Adjective to fill the blank in each case is:

Mi madre es muy trabajadora: es artista y también enseña en una universidad. A los estudiantes les gusta mi madre porque es una profesora buena, pero ella da exámenes muy difíciles. Este semestre enseña dos clases de arte chino. Mi madre es una gran mujer, ¿verdad?

Adjectives.

Adjectives are the characteristics that describe a noun, and can have gender (male or female) and number (singular or plural). Below are the different forms an adjective can take, using as an example "buena:"

Buena: singular and female Buenas: plural and female Bueno: singular and male Buenos: plural and male

Therefore, to use the appropriate adjective, the gender and number of the noun to be characterized must be identified and then an adjective with the same guidelines must be used.

If you want to learn more about Adjectives in Spanish, you can visit the following link: link

Ithink it has to be c. humans