Choice C is the best answer. In lines 63-64 ("We... proposal"), Akira says to Chie, "Please don't judge my candidacy by the unseemliness of this proposal." This reveals Akira's concern that Chie may say no to the proposal simply because Akira did not follow traditional practices.
Choices A, B, and D do not provide the best evidence for the answer to the previous question. Choice A is incorrect because line 33 ("His...refined") merely describes Akira's voice as "soft, refined." Choice B is incorrect because lines 49-51 ("You... mind")reflect Chie's perspective, not Akira's. Choice D is incorrect because lines 71-72 ("Eager... face") indicate only that Akira was speaking in an eager and forthright matter.