Organisms are given scientific names because :

Both (1) and (3)

The correct answer is Option (4) -Both (1) and (3)

In order to facilitate the study, number of scientists have established procedures to assign a scientific name to each known organism. This is acceptable to biologists all over the world. For plants, scientific names are based on agreed principles and criteria, which are provided in International Code for Botanical Nomenclature (ICBN). 

Animal taxonomists have evolved International Code of Zoological Nomenclature (ICZN). The scientific names ensure that each organism has only one name.

Description of any organism should enable the people (in any part of the world) to arrive at the same name. They also ensure that such a name has not been used for any other known organism.

Biologists follow universally accepted principles to provide scientific names to known organisms.

Each name has two components – the Generic name and the specific epithet. This system of providing a name with two components is called Binomial nomenclature.

This naming system given by Carolus Linnaeus is being practised by biologists all over the world.