In an examination containing 10 questions, each correct answer is awarded 2 marks, each incorrect answer is awarded-1 and each unattempted question is awarded zero. Which of the following CANNOT be a possible score in the examination?

Total number of questions:10.
Marks for each question:
Correct Answer:+2 marks.
Incorrect Answer:−1 mark.
Unattempt Question:0 marks.

Total number of questions: x+ y +z =10, where:
x: Number of correct answers.
y: Number of incorrect answers.
z: Number of unattempt questions.

x + y + z =10,
Score = 2x − y.

For 19
2x−y=19.
Rearrange: y=2x−19.
x +y+ z=10:
x+(2x−19)+z=10
3x+z=29

x  > 9, which is impossible since the maximum number of correct answers is 10.
Score is not achievable.

Thus the correct answer is option (A) 19