Please help me with Matlab code, all questions please

2. , 3.0) >> a=ones(3,3); If >> x = [1, 2, -3]; >>a(2,:) = x.^2; after executing what is the maximum value of all the elements in a ? 9 B 2 C 3 D D 6 1. 3.0) Which command is used to add text as a title at the top of the current figure? A diary B xlabel axis D title 3. , 3.0) Which command is used to list all variables from the current workspace? A doc B help C diary D whos 4. 3.0) Given the following code: [val, index]=max((-3,5,7,2*pi)) Which answer is right? A val=7 B index=5 index=-3 D D val=6.2832 5. 3.0) Given the following code: val=mean((-3,5,7,3]) Which answer is right? A val=3 B val=5 val=7 D val=-3