Answer: b) Conditional knowledge
Explanation:
Conditional knowledge is the knowledge that depicts about when to use or when not to use particular procedure, strategies, skills, abilities etc.The reason for using such strategy and procedure is also known.
According to the question, Ashton is using conditional knowledge as she knows when and why to apply particular formula for math problem as per result obtained from applying formula.
Other options are incorrect because procedural knowledge,elaborative knowledge and declarative knowledge is not used by Ashton for deciding the formula for math problem. Thus, the correct option is option(b).