Choose the correct meaning of the words in bold that are taken from the reading passage

The students were studying Economics Simultaneously with Medicine.
Similarly B. parallel C. Continuously D. Conditionally

Starvation may lead to death if it stays long with the individual.

Some diseases have distinctive behavior on people of the same problem.
A.Different B. Dilution C.Disturbance D. Abusive
Which one is true?

A. parallel

C. Disturbance