The answer im positve is b.?
The <em>older violins</em> are more than one object, in this case its cannot be used, only their; <em>each violinist</em> could mean male or female, so it would be possible the use of his or her or their (applied for either),but there is only the latter option. The correct answer is their/their.
<em>The older violins no longer had their original parts, but each violinist played their instrument well.</em>
