Which one of the following does not give precipitate with ammonical cuprous chloride?

Question

$$\begin {array} {1 1} (a)\; H_3C-CH_2-C \equiv CH & \quad (b)\;H_3C-C \equiv CH \\ (c)\; HC \equiv CH & \quad (d)\; H_3C-C \equiv C-CH_3 \end {array}$$