Questions: What is the life span of an annual angiosperm?

The answer is the third one: within a year.

Explanation:

• Multiple years: This option is incorrect because annual angiosperms complete their life cycle in a single year, not over multiple years.
• One hundred years: This option is incorrect as it is far too long for the life span of an annual angiosperm. Annual plants do not live for such extended periods.
• Within a year: This option is correct because annual angiosperms germinate, grow, flower, produce seeds, and die all within a single year. This is the defining characteristic of annual plants.

In summary, the life span of an annual angiosperm is within a year.