The sentence that has a verb in the active voice is B. Guglielmo Marconi perfected a type of radio technology.
The rest of the sentences have their verbs in the passive voice. If you wanted to make a passive sentence out of B, you would say - A type of radio technology was perfected by Gugliermo Marconi.
A complex sentence has at least one independent clause plus at least one dependent clause
Although I was very angry, I didn't harm him at all.
were u looking 4 a sentence fix?
