答案：C

C 由 “would arrive there”可知这是一个虚拟条件句, 再由 “right away”可知从句是与将来事实相反的假设, 要用 If you were to/should start out, 在虚拟条件句中, 从句中如有 had, were, should时,可以省略if ,用倒装结构: had+主语+done ; were+主语+ to do; should+主语 +do。故答案为C。