Which of the following statements is true?

a. we need vitamin d from the sun so there is no unsafe exposure level.

b. from 10am to 4pm are the most dangerous hours for exposure to the sun.

c. there is only one kind of harmful uv ray from the sun.

d. spf 10 is the minimum for safe protection

B. From 10AM to 4PM are the most dangerous hours for exposure to the sun.

Option (B)

Explanation:

The sun releases ultraviolet radiations (UV radiations) which are harmful to the lives on earth and these radiations are constantly controlled by the atmosphere of the earth.

There are 3 different types of UV radiation. They are namely-

Ultraviolet radiation-A -> This radiation is responsible for causing wrinkles, premature aging and also causes skin diseases. This radiation can penetrate the earth's atmosphere and reaches the surface. Ultraviolet radiation-B -> This radiation is highly dangerous as it has the ability to cause skin cancer, but they enter the earth's atmosphere at a relatively very low amount. Ultraviolet radiation-C -> These are harmful radiations but do not reaches the earth's surface as the atmosphere of the earth does not allow to pass through it.

These UV radiations are released significantly between the time of 10 AM to 4 PM. So, exposure to these radiations is harmful.

Thus, the correct answer is option (B).

It depends on the subject for me. some exams are easier than others so i usually go through it and answer questions i know based on my general knowledge, then double check after. going through the lesson can a lot  because the exams can be  very lesson-specific, but sometimes they are ridiculously long so a lot of people don't take the time. i did find that, when i went through the lessons, i was making 100's on my exams vs strictly using + the internet and  i make 90's. 

No, you can become homeschooled, though.  you can't drop out unless you are in high school.i give you the best to you and your baby!   let me know if there is any way i can you!