Answer: Fight one big battle instead of fight small three battles.
Explanation:
Since we have given that
Probability of winning the large battle = 0.56
Probability of winning each of the small battles = 0.78
Since the victories or defeat in the small battles are independent.
So, Probability of all three small battles to win the campaign is given by

Since 0.56 which is a probability of winning the large battles is more than the probability of winning all three small battles.
So, Large battle would win.
Hence, Fight one big battle instead of fight small three battles.