Answer:
E (EcoRI) B (BamHI) H (HindIII) X (XbaI) N (NotI).
Explanation:
Only SmaI does not have a recognition site in the polylinker of pCDNA vector (See map attached). So, in theory, any of the other enzymes: E (EcoRI) B (BamHI) H (HindIII) X (XbaI) N (NotI) could be used. It would be of importance to see in silico the digestion of regions flanking the p53 gene.