Question $18($Mandatory$)(1$ point$)$

In the capacitor discharge formula $q=q_0{e}^{-\frac{t}{R}C}$ the symbol $t$ represents:

the time constant

the time it takes for $C$ to lose the fraction $\frac{1}{e}$ of its initial charge

the time it takes for $C$ to lose the fraction $(1-\frac{1}{e})$ of its initial charge

the time it takes for C to lose essentially all of its initial charge

none of the above