Correct Answer: gallant

Solution : The third option is correct.

In this context, the adjective gallant describes the Serbians as brave, courageous, or noble, which is a fitting description if they were participating in fierce fighting.

The meanings of the other options are as follows:

• Cowardly: It means lacking courage.
• Unabashed: It means not embarrassed or ashamed.
• Bore : It means making a hole in something.

Therefore, the complete sentence is: In the early autumn fierce fighting took place, the gallant Serbians bearing a prominent part.