The questions are based on the trading and Valuation concept of Option

a$)$ What is the rationale behind the implementation of a stop$-$loss trading rule for the seller or writer of an out$-$of$-$the$-$money call option, and why does this particular strategy tend to offer a suboptimal hedge against potential losses?

b$)$ Could you elucidate the notion of valuation as it pertains to dividend$-$paying stocks within the context of American call and European call options, with a specific focus on the determination of intrinsic value?