Concept: This question tests the understanding of the mechanism and stoichiometry of the sodium-potassium pump (Na+/K+-ATPase), a crucial active transport system in animal cells.

Why (A) is correct: The sodium-potassium pump is an active transporter that moves ions against their concentration gradients. For every molecule of ATP hydrolyzed, it actively transports three sodium ions (3Na${}^{+}$) out of the cell and two potassium ions (2K${}^{+}$) into the cell. This creates an electrochemical gradient essential for nerve impulse transmission, muscle contraction, and maintaining cell volume.

Why other options are wrong:

• (B) 3Na${}^{+}$ inside for 2K${}^{+}$ outwards the cell: Incorrect direction for both ions.
• (C) 2Na${}^{+}$ outwards for 3K${}^{+}$ inside the cell: Incorrect stoichiometry and direction for potassium.
• (D) 2Na${}^{+}$ inside for 3K${}^{+}$ outwards the cell: Incorrect stoichiometry and direction for both ions.

Common Mistake: Students often confuse the number of ions transported or their direction of movement. Remember that sodium is pumped out, and potassium is pumped in.

NEET Tip: Think of it as "Na-Out, K-In" and the ratio "3-2". Sodium (Na) has 3 letters, so 3 Na${}^{+}$ go out. Potassium (K) has 2 letters (in its symbol), so 2 K${}^{+}$ go in. Also, remember it's an electrogenic pump because it moves a net positive charge out of the cell (3 positive out, 2 positive in = net 1 positive out).

Correct Answer: (A)