In Relation to the Expense Associated with the Creation of an Allowance

In relation to the expense associated with the creation of an allowance for doubtful debts,the UK Taxation Authorities:

A) never allows a deduction for taxation purposes for that amount.
B) allows a deduction for taxation purposes for that amount when it is recognised as an expense.
C) allows a deduction for taxation purposes immediately.
D) allows a deduction for taxation purposes only when there is a bad debt written off against a credit customer's account.