To solve this problem, we need to understand the concept of double fertilization in flowering plants.$\newline$Double fertilization is a unique feature of angiosperms (flowering plants) and involves two key processes:$\newline \bullet$Syngamy:$\newline$ - This is the fusion of one male gamete with the egg cell to form a diploid zygote.$\newline \bullet$Triple fusion:$\newline$ - This involves the fusion of the second male gamete with two polar nuclei in the central cell of the embryo sac, resulting in a triploid primary endosperm nucleus.$\newline$Together, these two processes constitute double fertilization.$\newline$Now, let's analyze the options:$\newline \bullet$Option 1: Fusion of two male gametes with one egg - This is incorrect as it describes a scenario that does not occur in plants.$\newline \bullet$Option 2: Fusion of one male gamete with two polar nuclei - This describes only the triple fusion part of double fertilization.$\newline \bullet$Option 3: Fusion of two male gametes of a pollen tube with two different eggs - This is incorrect as it does not describe the process of double fertilization.$\newline \bullet$Option 4: Syngamy and triple fusion - This correctly describes the two processes involved in double fertilization.$\newline$Therefore, the correct option is Option 4.