Incomplete question. Answered based on available information.
The missing options read;
A. Handcuffed, Jack swam from Alcatraz to Fisherman's Wharf in San Francisco in 1955.
B. Jack LaLanne received a star on the Hollywood Walk of Fame in 2002.
C. In 1954, Jack set a world record by swimming the length of the Golden Gate Bridge.
D. In 1950, Jack started inventing many of the first exercise machines.
Answer:
<u>D. In 1950, Jack started inventing many of the first exercise machines.</u>
Explanation:
In the English language, one of the main use of the question mark symbol is to solicit or make a query about a particular action, subject or thing.
In the sentences above, we notice that saying, <em>"In 1950, Jack started inventing many of the first exercise machines" </em>best fits the box containing the question mark.