The correct answer is: D. Flint glass
Flint glass is a type of optical glass that is made from silica, soda ash, lime, and lead oxide. It is known for its high refractive index and dispersion, which make it ideal for use in optical instruments such as lenses, prisms, and filters.
Pyrex glass is a type of borosilicate glass that is made from silica, boric oxide, soda ash, and lime. It is known for its high thermal and chemical resistance, which make it ideal for use in laboratory equipment and cookware.
Soft glass is a type of soda-lime glass that is made from silica, soda ash, and lime. It is known for its low melting point and ease of working, which make it ideal for use in glassblowing and other types of glasswork.
Hard glass is a type of borosilicate glass that is made from silica, boric oxide, soda ash, and lime. It is known for its high strength and durability, which make it ideal for use in windows, bottles, and other types of glassware.