1) Marie Curie is the woman who discovered radium.
Explanation:
In the given sentences, the first one is a dependent clause while the second is an independent clause. And to join these two independent clauses, we can use the pronoun "who" to join the two.
By using the pronoun "who" to introduce the relative clause "discovered radium", the "who" refers to the subject of the sentence.
Therefore, the correct sentence is option 1 "Marie Curie is the woman who discovered radium."
<span>Unconverted
men walk over the pit of hell on a rotten covering, and there are
innumerable places in this covering so weak that they won't bear their
weight, and these places are not seen.</span>
