The correct answer is option 2, which states that biological catalysts (enzymes) speed up a chemical reaction, remain unchanged after the reaction, and function optimally at 37 °C.

Let`s analyze each option to better understand the answer:

Option 1: "1 only" suggests that biological catalysts only speed up a chemical reaction. This option is incorrect because enzymes also exhibit other properties, as mentioned in option 2.

Option 2: "1, 2, and 3" correctly states that biological catalysts speed up a chemical reaction, remain unchanged after the reaction, and function optimally at 37 °C.

Option 3: "2 and 3 only" suggests that biological catalysts only remain unchanged after a reaction and function optimally at 37 °C. This option is incorrect because enzymes also speed up chemical reactions.

Option 4: "1, 3, and 4" states that biological catalysts speed up a chemical reaction, function optimally at 37 °C, and do not have enzymatic activity. This option is incorrect because enzymes do have enzymatic activity.

Therefore, the correct answer is option 2, which correctly states the properties of biological catalysts.