Question

which sex chromosome(s) is(are) needed for life? a x b y c x and y

Explanation:

The X chromosome carries essential genes for survival. Females (XX) and males (XY) both have X chromosomes. There are cases like XO (Turner syndrome) where an individual has only one X chromosome and can still survive. However, there are no known cases of individuals without an X chromosome (e.g., YO) surviving as the Y chromosome does not carry enough essential genes for life on its own.

Answer:

A. X