Which of the following flowers is unisexual?

Papaya (Carica papaya) is unisexual, meaning individual plants bear either male or female flowers separately (dioecious species). Papaya plants can be male (staminate flowers only), female (pistillate flowers only), or bisexual (hermaphrodite) depending on genetic and environmental factors. In contrast, hibiscus, mustard, and rose are bisexual (perfect flowers) - each flower contains both stamens and carpels. Unisexual flowers are an adaptation to promote cross-pollination and prevent self-pollination, increasing genetic diversity in offspring. The presence of separate male and female plants is called dioecy.