What is the primary method of interment for human remains that involves placing them in the ground?

Burial is the primary method of interment for human remains, as it specifically involves placing the body in the ground. This traditional practice has been a common cultural and religious practice across different societies for centuries, serving as a means to honor the deceased and provide a final resting place.

In contrast, embalming is a technique used to preserve human remains for a period of time, typically prior to a funeral service, but it does not represent a method of interment. Cremation involves the incineration of the body, reducing it to ash and sometimes allowing for the remains to be scattered or kept in an urn, rather than placing them in the ground. Entombment involves placing the deceased in a crypt or mausoleum, which is not the same as burial in the ground.

The specificity of burial as the act of placing the body directly into the earth is what makes it the correct answer in this context.