Debye is a unit of
(A) rms velocity
(B) force
(C) specific gravity
(D) electric dipole moment

Hint So here is a small clue, the formula for electric dipole is equal to the magnitude of the charges multiplied by the distance between them given as:
$p = 2lq$

Complete Step by step solution
So, let’s first understand the unit and where it is adopted from.
Since, the Debye unit is the CGS unit.
So the CGS unit stands for centimetre–gram–second system of units’ metric system.
So by this we can better and clearly understand.
So the electric dipole moment is the product of magnitude of either charge or the distance between the charges is directed from negative to positive charges
$p = 2lq$
P is the dipole moment
2l is the distance between them
Q is the charges
So distance is measured by the SI unit which is metre.
And the charges are measured by an S.I unit which is a coulomb.
So, the SI composite (combination of two or more) units of electric dipole moment is the ampere second meter.
The Debye is a CGS of electric dipole moment and it is named in honour of the physicist Peter J. W. Debye.

After seeing all the explanations given above, the final answer is option d which is correct, that is electric dipole moment.

Note
Before going any kind of CGS unit first need to form a SI unit and then understand the formula from there the SI unit then turning them into a CGS unit that is centimetre–gram–second system. Remember the main S.I units of physics like for current it’s Ampere, for electric dipole moment it is Debye.