Corrosion or rusting is the deterioration of a metal. When the metal corrode, an oxide will form on the surface exposed to the corrosive medium (water, air). The weight of iron rust increases, due to the increased weight of oxygen which has combined with the iron. 
For example: iron + oxygen Fe2O3 or Fe3O4 that weight more than Fe. 
Note: The oxides are not so adherent to the metal surface and so maybe at first there is an increase in weight but the final result is a loss of metal and weight.

Ozone is an allotrope of oxygen, where allotrope means different forms of the same element for example carbon has got two allotrope in the form of diamond and graphite. Other type of oxygen allotrope are dioxygen and tetra oxygen.

Alkaloids are a group of naturally occurring chemical compounds that contain mostly basic nitrogen atoms. This group also includes some related compounds with neutral and even weakly acidic properties.

When Calcium oxide i.e. quick lime is added to water filled in a bucket, it reacts vigorously with water to produce slaked lime (calcium hydroxide) releasing a large amount of heat. It gives hissing sound.

A nuclear reactor, formerly known as an atomic pile, is a device used to initiate and control a sustained nuclear chain reaction. Nuclear reactors are used at nuclearpower plants for electricity generation and in propulsion of ships.

Kamakhya Temple, also known as Kamrup Kamakhya is located at Nilachal Hill in western part of Guwahati, Assam. The temple is dedicated to mother goddess Kamakhya. It is one of the oldest of 51 Shakti Pithas.

Virupaksha Temple is located in Hampi which is 350 km from Bangalore, in state of Karnataka in southern India, so option © is correct.

Konark Sun Temple is a 13th-century AD Sun Temple at Konark in Odisha, India. It is believed that the temple was built by king Narasimhadeva I of Eastern Ganga Dynasty in 1255 AD.

• Shree Siddhivinayak temple is a Hindu temple dedicated to LordShri Ganesha.

• It is located in Prabhadevi, Mumbai.

• It was originally built by Laxman Vithu and Deubai Patil on 19^thNovember 1801.

• It is one of the richest temples in Mumbai.

• Siddhivinayak is well known as "Navrachna Ganapati" or "Navasala Pavanara Ganapati" among devotees.