Asset Beta capital, only, structure, understand

Mechanic

The asset beta of a firm equals its equity beta if:
a. the company has no debt
b. the company has no equity
c. the company's debt equals its equity

The correct answer was A).
The formula for the asset beta is:

Asset Beta = Equity Beta (1/(1+((D/E)(1-t)))
Therefore, the two betas are identical only if the company has no debt in its capital structure (D = 0). If the company has no debt, then the asset beta must equal the equity beta.

I don't understand why the answer cannot also be B (E=0)?

Thanks!