Definition: In this task, you need to answer the given multiple-choice question on geometry. Classify your answers into 'a', 'b', 'c', 'd', and 'e'.
Input: Problem: when the oil from a circular cylinder leaked , the formula for the speed of the leak is v = kh ^ 2 , where h was the height of the remaining oil and k was constant . if the height of the cylinder is 4 , the speed of the leak is v a ™️ , when the height of the oil remaining is 12 , what was the speed of the leak , in terms of v a ™️ ?
Options: ['a ) 9 v a ™️', 'b ) 4 v a ™️', 'c ) v a ™️ / 2', 'd ) v a ™️ / 4', 'e ) v a ™️']
Output:
a