Each of A, B, C, M, N and O has scored different marks. Only two people have scored between O and B. Only one person has scored more than M. Only three people have scored between M and O. N has scored more than C but less than A. How many people have scored less than C?

The correct option is One.

Let us step-by-step analyze the given statements to find the position/order of all 6 individuals (A, B, C, M, N, O) from highest marks (position 1) to lowest marks (position 6).

Step 1: Determine the total number of people and positions.
There are 6 individuals: A, B, C, M, N, and O.
Let us represent positions 1 to 6 from highest score to lowest score:
1 > 2 > 3 > 4 > 5 > 6

Step 2: Use the statement about M.
"Only one person has scored more than M."
This means M is at position 2.
Order so far: _ > M > _ > _ > _ > _

Step 3: Use the statement about M and O.
"Only three people have scored between M and O."
Since M is at position 2, the three people between M and O must be at positions 3, 4, and 5.
Therefore, O must be at position 6.
Order so far: _ > M > _ > _ > _ > O
Positions: 1: _, 2: M, 3: _, 4: _, 5: _, 6: O

Step 4: Use the statement about O and B.
"Only two people have scored between O and B."
Since O is at position 6, counting 2 positions up (positions 5 and 4) places B at position 3.
Order so far: _ > M > B > _ > _ > O
Positions: 1: _, 2: M, 3: B, 4: _, 5: _, 6: O

Step 5: Place the remaining individuals (A, N, C).
The remaining available positions are 1, 4, and 5.
The statement reads: "N has scored more than C but less than A."
This gives the relative order: A > N > C.
Placing A, N, and C in the remaining empty positions from highest to lowest:
- Position 1: A
- Position 4: N
- Position 5: C

Final Order from highest to lowest score:
1: A
2: M
3: B
4: N
5: C
6: O

Step 6: Answer the question.
The question asks: "How many people have scored less than C?"
Looking at the final order, only O (position 6) has scored less than C (position 5).
Therefore, exactly 1 person (only O) has scored less than C.