47. 缺乏維生素B1會使下列何種酵素反應受阻？ (A) 琥珀酸去氫酶 ( succinate dehydrogenase ) (B) 丙酮酸去氫酶 ( pyruvate dehydrogenase ) (C) 異檸檬酸去氫酶 ( isocitrate dehydrogenase ) (D) 乳酸去氫酶 ( lactate dehydrogenase )