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

Finally , after a bit of deliberation and general freaking out , Laura decided that she probably had enough to get me back to the Starbucks so we could both drive home . If she ran out of gas on the road , she would pull over and I 'd drive her home . Thankfully it did n't come to that .

Why might they be freaking out with Laura ?

[I] They were getting very low on gas .;
[II] None of the above choices .;
[III] They were unable to get to their car .;
[IV] Laura had ran out of gas during their trip .;...A:
[I]