Answer:
Variable and Fixed
Explanation:
Variable inputs are those which can be changed/altered in the short-run. The demand for these inputs can be changed with a change in production.
However, fixed inputs are those inputs which cannot be changed/altered in the short-run. The demand for these inputs remains unchanged in the short-run. It can only be changed in the long-run.
Since Brain has signed a lease obligation for the next three years, it cannot change the number of ovens in the short-run. This number of oven's is a fixed input at least for three years.
While, Brain can easily change the number of workers he wants to hire. Therefore, number of workers is a variable input in the short-run.
Thus, we can conclude that in the short run, these workers are variable inputs and the ovens are fixed inputs.