Final answer:
The question relates to exponentiation rules, specifically the power of a power property where (x^a)^b = x^(a · b). The appropriate response based on the rule is 'x^(a · b)'.
Step-by-step explanation:
The student's question seems to be related to the properties of exponents specifically the power of a power property, which is used when raising an exponentiated number to an additional power. This rule is expressed as (x^a)^b = x^(a · b). To answer the question, if x^a and x^b are given, applying the rule (x^a)^b = x^(a · b), the resulting expression after applying the exponent 'b' to the power 'a' would be x^(a · b), where 'a' multiplies 'b'.
Therefore, since the student's question includes the statement 'if x^a and x^b, then', the most suitable answer is 'x^(a · b)'. The question is incomplete and lacks full context, but based on the information provided, the rule states that the exponents multiply when an exponential expression is raised to another power.