If one lightbulb burns out, but the other bulbs remain lit, the circuit must be a
a. Parallel Circuit
c. Triangle Circuit
b. Series Circuit
d. Circle Circuit

Parallel Circuit

Explanation:

In a parallel circuit, there are multiple paths through which the current can flow, so the resistance of the overall circuit is lower than it would be if only one path was available.

explanation:

c is having 4 valence electrons and is bonded to three hydrogens and one sulphur atom, therefore, the number of bond pair is equal to four. as all the valence electrons are used in forming the bonds so, there is no lone pair left on carbon.

s is having 6 valence electrons and is bonded to one other sulfur atom and one carbon atom, therefore, the number of bond pair is equal to 2. as only two valence electrons are used in forming the bonds so, four electrons are left. therefore, two lone pairs are present on s.