Burning of coal and petroleum leads to which one of the following harmful events for the entire world?

1. results in global warming
2. produces smoke
3. produces energy
4. runs industries

Choose the correct combination.

1. only A1 and B2 are correct.
2. only B2 and C3 are correct.
3. only A1 and D4 are correct.
4. only B2 and D4 are correct.

Choose from the following the right combination of ferrous minerals.

1. copper and iron ore
2. bauxite and iron ore
3. manganese and iron ore
4. coal and copper

Two statements are given in the question below as Assertion (A) and Reason (R). Read the statement and choose the appropriate option:

Assertion (A): Minerals such as coal and natural gas are called energy minerals.

Reason (R): They provide heat and electric energy.

1. Both (A) and (R) are true and (R) is the correct explanation of (A).
2. Both (A) and (R) are true and (R) is not the correct explanation of (A).
3. (A) is true but (R) is false.
4. (A) is false and (R) is true.