In a class on matrices, the teacher defined the concept of the orthogonal matrix to students and went further by citing its properties, saying that the module of the determinant of an orthogonal matrix is always equal to 1 and also the applications in matrix decomposition and linear transformations of rotation. After the explanation, the teacher gave an example of an orthogonal matrix of order 3. One of the students managed, however, to copy only two of its lines, reproduced below:

At home, remembering that it was an orthogonal matrix, the student could conclude that the third line could be:

a) 2/3, -2/3 e 1/3

b) 1/3, 2/3 e 2/3

c) 2/3, 1/3 e -2/3

d) 1/3, -2/3 e 1/3

e) 2/3, 1/3 e 2/3