Final answer:
The question asks what 1 fluid dram is equal to, with the correct answer being 1 fluid dram. This is straightforward as the unit is equal to itself by definition, and the key comparison is that 1 fluid ounce contains 16 fluid drams.
Step-by-step explanation:
The question is asking to identify what 1 fluid dram (fl dr) is equal to. Options provided are 1 gallon, 1 fluid ounce, 1 fluid dram, and 1 milliliter. The answer is 1 fluid dram. This is because the question itself provides the direct conversion, indicating that 1 fluid dram is equal to itself. This is a basic unit conversion question where the answer is essentially in the question.
When comparing to other units, it is important to remember that 1 fluid ounce is a larger unit than a fluid dram. In the conventional system of measurement, there are 16 fluid drams in 1 fluid ounce. Therefore, if we were comparing to a fluid ounce, we would use a fractional value less than 1, not the full unit itself.