Explanation

To solve the problem, follow these steps:

1: Determine B's efficiency compared to A:

• A can finish the work in 40 days, so A's work rate is  1/40 of the work per day.
  
• If B is 255% less efficient than A, it means B's efficiency is reduced by 255%, which implies B is not practically effective (usually considered inefficient or not working effectively in real terms).

2: Calculate B's efficiency:

• If B is 255% less efficient, B's effective efficiency would be negative, which isn't practically feasible. To make sense of this:
• Assume B’s efficiency is effectively lower compared to A in realistic scenarios.

3: Adjust B's effective efficiency for practical calculations:

• Let's use a model where B is significantly less efficient but not zero. For instance, if B’s efficiency is assumed to be around 10% of A’s for simplicity:
• B can do the work in approximately 400 days.

The closest feasible answer given practical scenarios and combined work rate calculations is None.