Yes, winning means showing you can do it, and it feels great to accomplish something! No, winning doesn't make your ability to do anything any less. Some people believe winning is everything, but to win you must lose first and learn.
Oral language because it is the system through which we use spoken words to express knowledge, ideas, and feelings. Developing ELs' oral language, then, means developing the skills and knowledge that go into listening and speaking—all of which have a strong relationship to reading comprehension and to writing.
The answer is D because it states an hypothetical situation, as you explained above.