What technology helped Galileo, Hooke and Leeuwenhoek make discoveries based on observations that no one had ever seen? 1.They invented optical microscopes and telescopes so they could make discoveries.
2.They all made discoveries based using instruments that optical technology.
3.They all made discoveries using optical microscopes.
4.They all made discoveries using optical telescopes.

It is number 2. They all made discoveries based using instruments that optical technology

Explanation:

Leeuwenhoek revolutionized microscopy by crafting microscopes with high magnifying power, which enabled him to be the first person to observe microbiotic life, Hooke is known for his discovery of the law of elasticity for his first use of the word cell in the sense of a basic unit of organisms while describing the microscopic cavities in cork, and The science of astronomy took a huge leap forward in the first decade of the 1600s with the invention of the optical telescope and its use to study the night sky. Galileo Galilei did not invent the telescope but was the first to use it systematically to observe celestial objects and record his discoveries.