Multiple choice:The following figure shows a Turing machine illustrated by the state transition diagram. Its letter set is {V, C, +, =, "space",;}; State set {S1, S2, S3, S4, S5, S6,

The following figure shows a Turing machine illustrated by the state transition diagram. Its letter set is {V, C, +, =, "space",;}; State set {S1, S2, S3, S4, S5, S6, S7}, where S1 is the starting state and S7 is the ending state; The arrow indicates the state transition, and the label on it, such as < in, out, direction > indicates that when the input is in, the output is out, moves one lattice to the direction, and converts the state in the direction of the arrow, where in and out are symbols in the alphabet set, null means nothing, and the direction can be r (move right), l (move left), n (stay in the original place).  

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The function of the Turing machine is to.
@[D](2)
A. Be able to identify "V = C + C;" Symbol string of form;
B. Can recognize "V = C;" Symbol string of form;
C. Can remove the space in the symbol string;  
D. All of the above can be identified.




A. Be able to identify "V = C + C;" Symbol string of form;
B. Can recognize "V = C;" Symbol string of form;
C. Can remove the space in the symbol string;  
D. All of the above can be identified.


answer：D