The alkane formed by hydrogenation of (S)-4-methyl-1-hexyne is optically active, but the one formed by hydrogenation of

Question:

The alkane formed by hydrogenation of (S)-4-methyl-1-hexyne is optically active, but the one formed by hydrogenation of (S)-3-methyl-1-pentyne is not. Explain. Would you expect the products of hydrogenation of these two compounds in the presence of Lindlar palladium to be optically active?