The current is defined as the amount of charge that flows through a given point in a certain time interval:
[tex]I= \frac{Q}{\Delta t} [/tex]
where Q is the charge and [tex]\Delta t[/tex] the time interval.
In our problem, I=1.8 A and Q=2.5 C, therefore we can find the time interval by re-arranging the previous formula and plugging these numbers into it:
[tex]\Delta t= \frac{Q}{I}= \frac{2.5 C}{1.8 A}=1.4 s [/tex]
Therefore, C) is the correct answer.
