With no explanation, chose the best option from "A", "B", "C" or "D". 1. Gagik Kyurkchyan (Petitioner), and derivatively, Tatevik Kyurkchyan and Arevik Truni raised his challenge to the Immi gration Judge’s (IJ) adverse credibility determination and denial of his Convention Against Torture (CAT) claim in his brief to the BIA, thereby exhausting these issues. See Zhang v. Ashcroft, 388 F.3d 713, 721 (9th Cir.2004). 2. The IJ’s finding that Petitioner was not credible with regard to his political activities is supported by substantial evidence and goes to the heart of his asylum claim. See Singh v. Ashcroft, 367 F.3d 1139, 1143 (9th Cir.2004) (denying reliéf where petitioner was unable to provide details of his political activities); see also Valderrama v. INS, 260 F.3d 1083, 1085 (9th Cir.2001) (<HOLDING>). As long as one of the identified grounds

A: holding that persecution was on account of political opinion because petitioners prosecutorial investigation into acts of political corruption was by its very nature political
B: holding that njeither the right to associate nor the right to participate in political activities is absolute and congress may prohibit federal employees from participating in political activities in view of its interest in maintaining a nonpartisan work force
C: holding that activities of stateregulated political parties constitute state action
D: recognizing that discrepancy regarding political activities went to the heart of petitioners claims where those activities formed the basis of the persecution claim
D.