What is the answer for 25 please tell me smart people

I'd say your answer is D) Headache.

Explanation:

A headache isn't really visible and can't necessarily be measured, whereas all the other answer choices are both visible and can be measured in some way, shape, or form.

Most likely headache.

Explanation:

Jaundice can be seen from the yellowness from the skin, and if a person has fatigue.

Cyanosis can be seen from the bluish/greenish hue on a person's skin.

And heavy breathing can just be heard.

during the process of dna replication, brdu can replace thymidine and incorporate into the newly synthesized dna, cell proliferation thus can be reflected in the extent of brdu incorporation.