Look at the four schematic symbols shown in the figure above. each of the symbols is labeled with a number. which of the following statements about these symbols is correct?

a. symbol 1 represents a wire connection, symbol 2 represents a battery, symbol 3 represents a variable resistor, and symbol 4 represents a fuse.
b. symbol 1 represents a fuse, symbol 2 represents a fixed resistor, symbol 3 represents a battery, and symbol 4 represents an spst switch.
c. symbol 1 represents a fixed resistor, symbol 2 represents a fuse, symbol 3 represents a relay coil, and symbol 4 represents a lightbulb.
d. symbol 1 represents a battery, symbol 2 represents a lightbulb, symbol 3 represents a fuse, and symbol 4 represents a relay coil.