For option (A),

A minor is the determinant of the square matrix formed by deleting one row and one column from some larger square matrix.

So, the order of minor is always less than the order of determinant.

Thus, option (A) is correct.

For option (B),

A cofactor is the number you get when you remove the column and row of a designated element in a matrix, which is just a numerical grid in the form of a rectangle or a square.

A minor is the determinant of the square matrix formed by deleting one row and one column from some larger square matrix.

Since, the definition of cofactor and minor is same, then we can conclude that

Minor of an element is always equal to cofactor of the same element.

Thus, option (B) is incorrect.

For option (C),

Determinant of 3 × 3 matrix is given as,

Or,

Or using the definition of cofactors,

Thus, option (C) is correct.

For option (D),

A cofactor is the number you get when you remove the column and row of a designated element in a matrix, which is just a numerical grid in the form of a rectangle or a square.

A minor is the determinant of the square matrix formed by deleting one row and one column from some larger square matrix.

Since, the definition of cofactor and minor is same, then we can say that,

Minor of an element is always equal to cofactor of the same element.

⇒ The order of the minor and cofactor of A is same. (where A is some matrix)

Thus, option (D) is correct.