HELP! By now it was dawn, but the light was still dim and faint. The buildings round us were already tottering. . . . This finally decided us to leave the town. Once beyond the buildings we stopped, and there we had some . . . experiences which thoroughly alarmed us. The carriages . . . began to run in different directions though the ground was quite level. . . . We also saw the sea sucked away and apparently forced back by the earthquake: at any rate it receded from the shore so that quantities of sea creatures were left stranded on dry sand. On the landward side a fearful black cloud was rent by forked and quivering bursts of flame, and parted to reveal great tongues of fire, like flashes of lightning magnified in size.”
—Pliny the Younger,
as quoted in Eyewitness to History

“On the landward side” means
a.
away from the volcano.
c.
on the far side of the bay.
b.
toward the volcano.
d.
on the sea floor.