In A, you should put the date before “the Titanic” to make it sound more natural. So “On April 15, 1912, the Titanic hit an iceberg...”

You need a comma since you’ve separated the subject from the verb. The Titanic, on April 15, 1912, hit an iceberg... It otherwise sounds like it’s a name, “The Titanic on April 15, 1912.”

Option A is more or less fine, except for some minor punctuation details. It would help if you told us which test this question is from. The best way to combine the sentences would depend on the context, but since you’re Chinese, you’re probably wondering how to do it with a relative clause: On April 15, 1912, the Titanic, (which was / had been) considered an unsinkable ship, hit an iceberg in the Atlantic Ocean and sank. Make sure you use the commas around the relative clause, since it is non-defining / non-restrictive.

A.The Titanic on April 15, 1912, hit an iceberg and sank even though it was considered unsinkable Jason is correct, you need a comma after the word "sank". In addition, the word order is not good. "on April 15, 1912" is not in the correct place. The normal word order in English is: Subject - verb - object - place - manner - time The Titanic (s) hit (v) and iceberg (o) on April 15, 1912. In your sentence, because you have additional information, I would say: On April 15, 1912, the Titanic, considered an 'unsinkable ship', hit an iceberg in the Atlantic Ocean, and sank.

You need a comma since you’ve separated the subject from the verb. The Titanic, on April 15, 1912, hit an iceberg... It otherwise sounds like it’s a name, “The Titanic on April 15, 1912.”