At 373 K, a gaseous reaction A→2B+C is found to be of first order. Starting with pure A, the total pressure at the end of 10 min was 176 mm of Hg and after a long time when A was completely dissociated, it was 270 mm of Hg. The pressure of A at the end of 10 minutes was:
(a) 94 mm of Hg
(b) 47 mm of Hg
(c) 43 mm of Hg
(d) 90 mm of Hg