please explain

40. Feng starts a new job on July 1 and becomes covered under the employer's health insurance plan which has an annual deductible of $2,400. Feng contributes the maximum amount into a Health Savings Account. Which of the following statements regarding Feng's Health Savings Account is correct? A) Feng can contribute and deduct $1,200 for AGI. B) Feng's contribution will be deductible if he itemizes, and the contribution along with his out- of-pocket medical expenses exceed 7.5% of AGI. C) If Feng withdraws $500 to pay for X-rays, the $500 is taxable. D) Interest income earned on the HCA is taxable