According to the double entry system of accounting, an account that obtains benefit is: A) Credit B) Debit C) Income

Credite

Benefit? if sale than cr, if assets than dr, if salary than dr, if loan than cr

A) Credit

In double entry system all the debits and credits must be equal

depends...
if it is an asset account gaining benefit then it is debited..
if income/equity account gaining benefit then it is credited...

According to the double entry transaction, the account that receives benefit is the one to be debited. While the other account on the other hand is credited

A) Credit.

Question is incomplete and has undefined scope. "Account" in accounting has a very broad scope, whithout specifying type of account its impossible to answer. otherwise all given answer A, B & C are correct for different types of accounts. 

all options can be included, but usually assets defined as a resource from which economic benefits are expected to flow into entity (IFRS)

if assets then debit,

According to the double entry system of accounting, an account that obtains benefit is: B) Debit Accounting Rule : Debit the receiver Credit the giver

it can be all of them

it depends on the account type