A debit in a nominal account denotes . .... ? (a) income (b) loss (c) revenue (d) expense

The Nominal accounts are temporary accounts which are closed at the end of each year by moving their balances to Permanent accounts. Accounts that come under this type are expenses, gains, revenues, losses. The balance of these accounts becomes assets or losses at the end of year and moved to permanent accounts. The accounting rule that is used for this type of accounts is "Debit all expenses and losses" and "credit all incomes and gains". While paying the salary to the employees in cash, the amount is debited from the salary account (nominal account). If a discount is got from a company then it is credited to the discounts account.

loss & expense

D. is correct

What is this?

Debit all expenses and losses

Answer D is correct

Expense and Loss

Debit in Nominal account denotes : Expenses or Losses

LOSS

A debit in nominal account means an increase in either a B or D, or decrease in A or C. Technically, the question is not valid,  the answer depends on the movement of each option. It could be all of the above. 

The opponent is of expenses and thus holds the profit and loss account is

Loss