1. Hiss was serving as head of the Endowment on Aug 3, 1948, when Whittaker Chambers reluctantly appeared before the House Un-American activities Committee.
A. Chambers, a portly hunchbacked man with a melodramatic style, had been a Communist courier but had broken with the party in 1938.
B. When Nixon arranged a meeting of the two men in New York, Chambers repeated his charges and Hiss his denials.
C. Summoned as a witness, Hiss denied that he had ever been a Communist or had known Chambers.
D. He told the Committee that among the members of a secret Communist cell in Washington during the 30s was Hiss.
6. Then, bizarrely, Hiss asked chambers to open his mouth. (CAT 1996)
Option (c)
From the sentences; we can make out that Chambers is pressing charges and Hiss is in denial.
Thus, the "HE" in sentence D should follow A. Once the charges were pressed; Hiss was summoned. This gives us the logical link as DC. We now have the link ADC. Answer is option (c)