Final answer:
c) Cucumber is NOT from the Brassica family; the other options, kale, broccoli, and cauliflower, are from the Brassica genus.
Step-by-step explanation:
The plant that is NOT from the Brassica family among the options provided is cucumber. Kale, broccoli, and cauliflower are all members of the Brassica genus, specifically Brassica oleracea. This genus includes a variety of vegetables that have been cultivated over time; some other members are Brussel sprouts, cabbage, and kohlrabi.
On the other hand, cucumber belongs to the gourd family, Cucurbitaceae, and is not related to the plants in the Brassica genus.