I'm at a loss about how to approach this issue:
Suppose that we know that parameterized problem $B$ can be solved in time $\mathcal O^*(3^k)$. Furthermore, there is a parameterized reduction from problem $A$ to problem $B$ that runs in polynomial time. What running time bound can we give for problem $A$ if we know that the reduction creates new instances with parameter
(a) at most $4k$,
(b) at most $2k^2$?