What is the desired dose if the available dose is 300 mg and you need a 900 mg dose?

To determine the desired dose in this scenario, it's important to understand that the question clearly states the need for a 900 mg dose. The available option of 300 mg indicates how much of the medication is available for administration, but it does not change the fact that the required amount to meet the patient's needs is explicitly 900 mg.

Therefore, the desired dose is simply what is specified in the question itself, which is 900 mg. This aligns directly with the requirement stated, confirming that the correct choice is indeed the one that matches the needed dose for the patient’s treatment plan. This straightforward approach emphasizes the importance of understanding the difference between available drug quantities and the necessary dosage to achieve the intended therapeutic effect.