Read the following article and answer the question by choosing from the options.

Boy I ca nt believe this happened ! If I could turn around and kick myself i would lol ! I ' ve done it a million times without anything happening until ... on 7/25 I was unloading the truck and coming down from the liftgate with a cart full of oxygen tanks . Somehow the cart kept going right off the gate and took me with it .

Why did the narrator lose control of the cart with the tanks on it ?
Available choices:
(1). None of the above choices .;
(2). The hot July sun caused the to become woozy .;
(3). The narrator slipped on the icy ground .;
(4). The tanks were heavy causing the cart pull away from the narrator .;...A:
(4).