Before revision:  The asymptotic regime considered, in which the strike is made to converge to the spot stock price as the maturity approaches 0, is more relevant in applications since the most liquid options have strikes that  close to the spot price.
After revision:  The asymptotic regime considered, in which the strike is made to converge to the spot stock price as the maturity approaches zero, is relevant in applications since the most liquid options have strikes that close to the spot price.