Important advantages to raised-bed gardens are that they

conserve water and keep the soil moist

conserve water and space for growing and limit compaction of the soil

conserve water and never get weeds in the paths

conserve water and space for growing

A raised-bed garden is a type of gardening method in which the vegetables and other small plants are grown in garden boxes kept elevated above the ground. These garden boxes are kept separated from each other.

The advantages of having a raised-bed garden are:

1. The movement of harmful pest from crop to another is hindered.

2. It prevent the compaction of the soil.

3. It stops the propagation and growth of weeds from one box to another.

4. It provides better drainage of water from the soil.

5. The walls of the garden box prevent the erosion of the soil.

6. The garden boxes conserve space.

Hence the answer will be B. conserve water and space for growing and limit compaction of the soil.