Use the graph below to answer this question

ACTIVITY	PREDECESSOR	NORMAL TIME	NORMAL COST	CRASH TIME	CRASH COST
A	-	7 days	$6,000	6 days	$6,600
B	A	4 days	$1,200	2 days	$3,000
C	B	11 days	$4,000	9 days	$6,000

a. What action is the least expensive if you were to crash and reduce the critical path by 1 day/

b. Assuming no other paths are critical, what would you do to reduce the critical path by one additional day - the least expensive action?

c. What is the total cost of this 2-day reduction?

Group of answer choices

a: Reduce a = $600; b: Reduce b & c = $1900; c: Total Cost = $2500

a: Reduce a = $600; b: Reduce b = $900; c: Total Cost = $1500

a: Reduce a = $600; b: Reduce b = $1800; c: Total Cost = $2400