A. The verb tense is always present tense in this sentence unlike the others.
The last one ouch a connation is a feeling that adds to the meaning
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.
Marco Polo, an explorer from Venice, traveled overland to China.
