The term ''employment'' shall not include:

1. (a) service in agricultural labor, except as otherwise provided in subsection (b) of section 4A and section 8C, by an individual who is an alien admitted to the United States to perform agricultural labor pursuant to section 214(c) and 101(a)(15)(H) of the Immigration and Nationality Act;

   [There are no subsections (b) or (c).]