To solve this question, you need to identify the predatory insect that lunges forward with its two front forelegs to catch its prey.

A. Spider: Spiders do not lunge forward with their front forelegs to catch prey. They typically use their webs or stealth to capture prey.

B. Praying Mantis: Praying mantises are known for their unique front forelegs, which are adapted for catching and grasping prey. They can indeed lunge forward to catch their prey, making this the most accurate option.

C. Goliath beetle: Goliath beetles are not predatory insects. They are herbivorous and feed on fruits, tree sap, and other plant material.

D. Moth: Moths do not typically lunge forward with their front forelegs to catch prey. They have different feeding mechanisms, such as using their proboscis to suck nectar from flowers.

Therefore, the correct answer is B. Praying Mantis.