Option 1: Strawberry - The correct answer is option 1. Strawberries are unique because their seeds are actually located on the outside of the fruit. These seeds are small, brown, and positioned on the outer surface of the strawberry. Unlike most other fruits, where the seeds are found inside the fleshy part, strawberries have their seeds exterior to the fruit itself. This is one of the characteristics that make strawberries different from other fruits.

Option 2: Banana - The seeds of a banana are actually located inside the fruit. Though they are small and not easily detectable, they are present within the fruit`s flesh and are not found on the outside of the fruit.

Option 3: Groundnut - Groundnuts are not fruits. They are a type of legume and therefore do not have seeds outside like a fruit.

Option 4: Cashew nut - Cashew nuts are also not fruits. They are seeds that hang outside a fruit-like structure called the cashew apple. However, the actual cashew nut itself is not the fruit, so the seed of cashew is not located outside a fruit.

So, the correct answer for a fruit with its seed outside is option 1, Strawberry.