Why do we need to use telescopes that are sensitive to other types of radiation

According to social exchange theory, altruistic behaviors benefit the individual who performs them.

For general projectile motion, when the projectile is at the highest point of its trajectory, its acceleration is zero? a)the horizontal and vertical components of its velocity are zero. b) its velocity is perpendicular to the acceleration. c)the horizontal component of its velocity is zero. d)its velocity and acceleration are both zero.

Iwill give brainliest if you answer right : )