Answer:
B. pay the strike price for the security in 2 business days
Explanation:
A call option confers a right (and not the obligation) on the buyer to buy(call) an underlying asset at a pre determined strike/exercise price at a specified future date.
A call buyer exercises his option only when it is beneficial to him and his profit is expressed as
= Current Market Price(CMP) as on expiry - Strike price - Option premium paid
Once a call buyer exercises his right to call/buy an underlying asset i.e equity stock here, he is required to pay the strike price for the security within 2 business days.