Subject to subsection (b), a person entitled to educational assistance under this chapter is entitled to receive a monthly subsistence allowance during any period for which educational assistance is provided such person. The amount of a subsistence allowance under this section is $300 per month, adjusted in accordance with
section 2145 of this title, in the case of a person pursuing a course of instruction on a full-time basis and is one-half of such amount (as so adjusted) in the case of a person pursuing a course of instruction on less than a full-time basis.