The Clue Bank a/c : Money :: Demat a/c : ___
The Answer SHARE
A bank account holds money, while a demat account holds shares. Just like you can deposit and withdraw cash from a bank account, a demat account allows you to buy and sell shares. Therefore, the relationship between a demat account and shares is similar to that of a bank account and money. This is why "share" is the correct answer for the clue.