Question

the times determine heats and lane assignments during the preliminaries.

in this sentence, preliminaries means:

• tricks intended to gain an advantage

• minor matches preceding the main event

• formal events performed on special occasions

• journeys by boat or aircraft

Explanation:

The sentence is about determining heats and lane assignments during a certain stage. "Preliminaries" in the context of a competition - related scenario (like heats and lane assignments which are common in sports competitions) refers to the minor matches (preliminary races, etc.) that happen before the main event. The other options: "tricks intended to gain an advantage" has no relation to the context of heats and lane assignments; "formal events performed on special occasions" is too broad and not relevant to the sports - competition - related context; "journeys by boat or aircraft" is completely off - topic.

Answer:

minor matches preceding the main event