please make sure to provide correct solution, do not answer if you are unsure as this creates confusion. Thank you

A rock breaks loose from the edge of a cliff and falls straight down. Ignore any effects from air resistance. The acceleration of the rock when it is half way to the ground is equal to /1 mark O a. 3.13 m/s? O b. 9.80 m/s? O c. 4.90 m/s2 O d. 19.6 m/s? O e. zero