Which of the following statements are true?
(i) An object will continue moving uniformly until the resultant force on it is zero.
(ii) The bodies do not change their state of rest or motion unless acted upon by an unbalanced external force.
(iii) If a body is at rest on the surface of the Earth, then the net downward Torce exer force exerted by the Earth and net upward force exerted on the body are not equal to each other.

Options

A. Only (i) and (ii)
B. Only (ii) and (iii)
C. Only (i) and (iii)
D. All (i), (ii) and (iii)

Explanation

To determine which of the statements are true, let's analyze each statement step by step:

### Step 1: Analyze Statement (i)
**Statement:** An object will continue moving uniformly until the resultant force on it is zero.

**Explanation:** According to Newton's First Law of Motion, an object at rest will stay at rest, and an object in motion will continue in motion with the same speed and in the same direction unless acted upon by a net external force. Therefore, if the resultant force on an object is zero, it will either remain at rest or continue moving uniformly.

**Conclusion:** This statement is **true**.

### Step 2: Analyze Statement (ii)
**Statement:** The bodies do not change their state of rest or motion unless acted upon by an unbalanced external force.

**Explanation:** This statement is a restatement of Newton's First Law of Motion. It indicates that an object will not change its state of motion (whether at rest or in motion) unless a net external force (unbalanced force) acts on it.

**Conclusion:** This statement is **true**.

### Step 3: Analyze Statement (iii)
**Statement:** If a body is at rest on the surface of the Earth, then the net downward force exerted by the Earth and the net upward force exerted on the body are not equal to each other.

**Explanation:** When a body is at rest on the surface of the Earth, it experiences two forces: the downward gravitational force (weight) exerted by the Earth and the upward normal force exerted by the surface. According to Newton's Third Law of Motion, these forces are equal in magnitude and opposite in direction when the body is in equilibrium (at rest). Therefore, the net downward force and net upward force must be equal.

**Conclusion:** This statement is **false**.

### Final Conclusion
Based on the analysis:
- Statement (i) is true.
- Statement (ii) is true.
- Statement (iii) is false.

Thus, the correct answer is that only statements (i) and (ii) are true.