Solder is an alloy of:

The correct answer is Tin and lead.

Explanation:

The correct answer is Option 3 i.e. Sn and Pb

• Electrical solder is an alloy of tin (Sn) and lead (Pb).
• Tin-Lead solder is the largest single group and the most widely used of soldering alloys.
• Soldering is a process in which two or more metal items are joined together by melting and flowing a filler metal into the joint.
• The filler metal has a relatively low melting point.
• A solder is a fusible metal alloy with a melting point or melting range of 90 to 450°C.
• The solder is melted in the process of soldering to join metallic surfaces.
• It is especially useful in electronics and plumbing.