Insurance companies primarily sought to make money by insuring many ships or assets, hoping to collect more in premiums than they would pay out in losses. This is reflected in your first option:
"By insuring many ships, the insurance company hoped to collect more in premiums than it would pay in losses."
This model of spreading risk is fundamental to the insurance industry, as it allows companies to profit by managing the collective risk of insuring a large number of clients. The other options either misrepresent the principles of insurance or suggest a strategy that is not typically followed in the industry.