However, with the current uncertainty within the mining sector, it seems prudent to stick to companies that are profitable now and, with Petra Diamonds offering stronger growth prospects at a more appealing price than Polyus Gold, it seems to be the pick of the three stocks at the present time.
What is the relationship between 'Polyus' and 'mining' in the context of the input sentence.
Options: employer, industry, headquarters location, chief executive officer