What's the Upper Bound (Maximum Value) of a Call Option? (FRM)

The maximum value a call option can take is the current
value of the underlying. In other words a call option whether it’s a American
option or an European option cannot be more valuable
than the value of its underlying.
For example a call option on a stock - the maximum
value the call option can take is the current stock price. If a call option is priced above the current value of the underlying then there will be
arbitrage opportunities , this means there could be gains made in the market without taking any risk.