Answer:
C) speed of the object increases by 9.8 m/s during each second of its motion.
Step-by-step explanation:
Acceleration due to gravity is calculated by

G = Gravitational constant = 6.67408 × 10⁻¹¹ m³/ kgs²
m = Mass of object
M = Mass of Earth = 5.972 × 10²⁴ kg
R = Radius of Earth = 6.371 × 10⁶ m
Plugging in the above values, we get
a = 9.8 m/s s
Acceleration due to gravity is denoted by 9.8 m/s² , this means that an object will change its velocity every second by 9.8.