Answer:
They are the most common type of joint.
Explanation:
Synovial joints are the most common type of joint found in the human body that move against each other. Synovial joints are also known as Diarthroses (freely movable) and it's examples are knee and shoulder.
Synovial joints are the most common type of joint because they are generally found in most of the joints such as ball and socket joint, condyloid joint, hin.ge joint, gliding joint, saddle joint and pivot joint. So, it is almost present in every joint of human beauty.
Hence, the correct answer is "They are the most common type of joint."
