please also explain the reason for each answer

Question 1 Multidimensional unconstrained optimization methods can be classified in different ways. If a method does not require derivative, it is called: A. Descent B. Ascent C. Gradient D. Direct Question 2 Cholesky in compare with the LU method is: A. a special case B. used when coefficient matrix has inverse C. more complex than LU method D. used when LU has no success Question 3 A matrix condition number: A. is an integer value B. is greater or equal than one C. is between zero and one D. does not require the norm. Question 4 General Linear Least Squares method: A. includes functions which are linear. B. is equivalent to multiple linear regression C. is equivalent to polynomial regression D. the terminology linear refers to the parameters Question 5 In interpolation: A. Newton method is always more accurate than Lagrange method B. Lagrange method is always more accurate than Newton method C. Both methods have the same accuracy D. none of above