The transpose of a matrix in C can be efficiently computed using:Two nested loopsRecursionPointersmemcpy() function

The transpose of a matrix in C can be efficiently computed using two nested loops. Here is a step-by-step guide on how to do it:

1. First, you need to define your matrix. In C, a matrix is typically represented as a two-dimensional array. For example, you might have a 3x3 matrix represented as int matrix[3][3];.

2. Next, you need to create a new matrix to hold the transpose. This will also be a 3x3 matrix, so you can define it as int transpose[3][3];.

3. Now you can start the process of transposing the matrix. This involves swapping the row and column indices for each element in the matrix. In other words, the element at position (i, j) in the original matrix will be at position (j, i) in the transpose.

4. To do this, you can use two nested loops. The outer loop will iterate over the rows of the matrix, and the inner loop will iterate over the columns. Here is what the code might look like:

for (int i = 0; i < 3; i++) {
    for (int j = 0; j < 3; j++) {
        transpose[j][i] = matrix[i][j];
    }
}

5. After these loops finish executing, the transpose matrix will be the transpose of the original matrix.

Note: The other options mentioned in the question (recursion, pointers, and the memcpy() function) can also be used to transpose a matrix in C, but they are typically less efficient or more complex than the nested loop approach.