The incorrect sentence is -

• Incorrect sentence: The statistic show that, in general, women live longer than men.
এবং এর, Correct sentence: The statistics show that, in general, women live longer than men.
- Statistics দেখতে plural হলেও এটি মূলত singular, তাই এর সাথে singular verb বসবে।

• Options:
• Cactus [Singular form]
English Meaning:  any of many types of desert plant, usually with sharp spines (= long points) and thick stems for storing water.
- এর তিনটি plural form হয়। 
- cacti or cactus or cactuses.
- Correct sentence: Cacti are well adapted to survive in arid environments.

• Index: [Singular form]
Plural form: Indices, Indexes.
Correct sentence: The index is divided into two sections.

• Singular: Bacterium - Plural: Bacteria.
Correct sentence: Bacteria are microscopic organisms that can be found almost everywhere on Earth.