Which of the following qualifies as a mechanical method to remove aquatic weeds?

• A. Hand pulling
• B. Spraying herbicide
• C. Releasing fish
• D. Water depth manipulation

Answer: (A)

Mechanical methods remove aquatic weeds through physical contact or disruption, using hands, tools, or equipment to lift, pull, cut, or scoop plants from the water. Hand pulling fits this because you directly grasp and remove the weed along with its roots. The other options rely on non-mechanical approaches: spraying herbicide uses a chemical to kill or suppress plants; releasing fish is a biological control that relies on grazers or predators; altering water depth changes the habitat to suppress growth but does not physically remove the plants. So, hand pulling is the mechanical method.