You have designed a new drug which halts cell division. Studies on its effects show cell after cell with the chromosomes lined up on the equatorial plane. Thus, your drug most likely blocks cells from moving out of ___.
A) prophase
B) telophase
C) metaphase
D) interphase
E) anaphase

Option-C

Explanation:

The M phase of the cell cycle proceeds in the four phases: prophase followed by metaphase then anaphase, and telophase.

These sub-phases can be easily distinguished as the genetic material move in the cell in various form and the changes become characteristic of the subphases.

During metaphase, the chromosomes are aligned at the center of the cell or at the imaginary equatorial plate.   Since it is mentioned that the drug shows its effect when the chromosomes are aligned at the equatorial plate therefore he is referring to the metaphase of the cycle.

Thus, metaphase is correct.

the answers are a and c