Cucumber (Cucumis sativus) is a widely cultivated plant in the gourd family, Cucurbitaceae. It is a creeping vine that bears cucumiform fruits that are used as vegetables. There are three main varieties of cucumber: slicing, pickling, and seedless.

**Family Plants with Tricarpellary, Syncarpous Unicellular Gynoecium with Inferior Ovary**

The correct answer is option 'D' - Cucurbitaceae.

**Explanation:**

1. **Tricarpellary**: The term "tricarpellary" refers to a gynoecium or female reproductive structure that is composed of three carpels. Carpels are the female reproductive organs of a flower.
2. **Syncarpous**: Syncarpous means that the carpels are fused together to form a single structure.
3. **Unicellular Gynoecium**: The gynoecium is the female reproductive part of a flower, consisting of one or more carpels. In this case, the gynoecium is unicellular, meaning it is composed of a single cell.
4. **Inferior Ovary**: The term "inferior ovary" refers to the position of the ovary in relation to the other floral parts. In an inferior ovary, the ovary is located below the attachment point of the other floral parts.

Now let's look at each option and determine which family plants meet the given characteristics:

a) **Asteraceae**: The Asteraceae family, also known as the daisy or sunflower family, typically has a syncarpous bicarpellary gynoecium. Therefore, it does not match the given characteristics and is not the correct answer.

b) **Cruciferae**: The Cruciferae family, also known as the mustard family, usually has a syncarpous bicarpellary gynoecium. Therefore, it does not match the given characteristics and is not the correct answer.

c) **Solanceae**: The Solanceae family, also known as the nightshade family, typically has a syncarpous bicarpellary or tricarpellary gynoecium. Therefore, it does not match the given characteristics and is not the correct answer.

d) **Cucurbitaceae**: The Cucurbitaceae family, also known as the gourd family, has a tricarpellary, syncarpous unicellular gynoecium with an inferior ovary. This matches the given characteristics and is the correct answer.

Therefore, the correct answer is option 'D' - Cucurbitaceae.