) If two half-open air columns A and B, that have identical lengths with one free and one fixed boundary, are subject to the same sound source frequency, what could explain why a wave may travel slower along column A compared to column B? Choose all that apply, and explain below. a) Column A has a slightly smaller diameter than column B. b) Column A is filled with argon gas, and column B is filled only with air. c) Column A and column B are identical in their fluid (i. e., air) density, except that the air in column A is at a higher temperature.