The correct option is
B Stroll
Option A; Stroll means to walk in a leisurely way and hence this is the correct option.
Option B; Gallop is the fastest pace of a horse. This is an incorrect option as it does not mean the aforesaid.
Option C; Jog is to run at a steady gentle pace and therefore this is an incorrect option.
Option D; Promenade is a paved public walk. Hence this is an incorrect option.