Consider the simplex tableau given below. \[ \left[\begin{array}{ccccc|c} x_{1} & x_{2} & s_{1} & s_{2} & p \\ 2 & 1 & 0 & -5 & 0 & 21 \\ 2 & 0 & 1 & -5 & 0 & 11 \\ \hline-3 & 0 & 0 & -2 & 1 & 24 \end{array}\right] \] (A) Which variables are basic variables? $\mathrm{x}_{2}, \mathrm{~s}_{1}$, and $\mathrm{P}$ $\mathrm{x}_{2}, \mathrm{~s}_{2}$, and $\mathrm{P}$ $\mathrm{x}_{2}, \mathrm{~s}_{1}$, and $\mathrm{s}_{2}$ $x_{1}, s_{1}$, and $s_{2}$

Step 1 ：Consider the simplex tableau given below.

Step 2 ：\[\left[\begin{array}{ccccc|c} x_{1} & x_{2} & s_{1} & s_{2} & p \\ 2 & 1 & 0 & -5 & 0 & 21 \\ 2 & 0 & 1 & -5 & 0 & 11 \\ \hline-3 & 0 & 0 & -2 & 1 & 24 \end{array}\right]\]

Step 3 ：The basic variables in a simplex tableau are those that have a coefficient of 1 in one row and 0 in all other rows.

Step 4 ：Looking at the given tableau, we can see that the variables \(x_{2}\), \(s_{1}\), and \(p\) are the basic variables because they satisfy this condition.

Step 5 ：Final Answer: The basic variables are \(\boxed{x_{2}, s_{1}, \text{and } p}\).