This is not an alloy of copper-

(A) Brass

(B) Bronze

(C) Solder

(D) Duralumin

The correct option is C

(C) Solder

The explanation for correct option

Correct option(C) - Solder

• Alloy is a mixture of metals.
• Solder is an alloy of Tin. So it is not the alloy of Copper. So this option is correct.

The explanation for incorrect options

Option (A) - Brass

• Brass is an alloy of Copper. Since it is an alloy of Copper this option is not correct for this question.

Option (B) - Bronze

• Bronze is an alloy of Copper. Since it is an alloy of Copper this option is not correct for this question.

Option (D) - Duralumin

• Duralumin is an alloy of Aluminium and Copper. It contains 5% Copper also. Since it is an alloy of Copper this option is not correct for this question.

Hence option (c) is the correct answer.