To spell the word occurrence, why is the final consonant doubled before adding the suffix?

a) because the suffix begins with a consonant
b) because the stress is on the second syllable of the base word ending in consonant + vowel + consonant
c) because the base word ends with two vowels before the final consonant
d)because the base word ends in two consonants

bravery and perseverance

explanation:

depends on your school

when i was in high school i took ap biology my senior year and it was the hardest one for me because my teacher finished the material within the first month of school and then went on to doing advanced college level it was horrible. but at a nearby school ap biology was one of the easier aps. also, it depends on what you are interested i like math a lot so ap calculus was easier for me than most but i hate history so ap us government was harder for me than most.