When you take the square root of $9$, don’t forget that there are two possibilities: one positive and one negative. Write two separate equations for $2t - 1$.

After you solve the two simple equations for $t$, compare both values to the answer choices and see which one appears.

In one line, type (2t - 1)^2 (Desmos will change t to x automatically). In another line, type 9. You will see the parabola $y = (2x - 1)^2$ and the horizontal line $y = 9$.

Click on each point where the parabola and the line intersect. Note the $x$-coordinates of these intersection points; these are the solutions for $t$.

Compare the $x$-coordinates you found to the answer choices $5$, $3$, $2$, and $1$, and identify which one of the choices matches a solution.

Start from the equation:

If a square equals 9, then the inside can be either $3$ or $-3$. So write two equations:

Solve $2t - 1 = 3$:

Solve $2t - 1 = -3$:

So the possible solutions to the equation are $t = 2$ and $t = -1$.

The answer choices are $5$, $3$, $2$, and $1$.

From the solutions $t = 2$ and $t = -1$, the only value that appears in the choices is $2$.

Therefore, the correct answer choice is $2$.