Apple Inc may notch its most successful holiday shopping season yet when it reports quarterly results on Monday, setting records for sales of its gift-friendly iPhones and iPads. It will, however, continue to draw investor scrutiny over sales in ultra-competitive China, its No. 2 market but a drag on revenue and margins in recent quarters. The iPhone maker has been ceding ground to Samsung Electronics and other rivals there, but has now sealed a long-awaited deal to sell iPhones through China Mobile that could bear fruit in 2014. Apple, which once routinely blew away Wall Streets most bullish expectations, needs a superb quarter to galvanize the stock.