Final answer:
The effective buffering range of imidazole (pKa = 6.95) is from 5.95 to 7.95, as buffers are most functional within ±1 pH unit of the pKa.
Step-by-step explanation:
The effective buffering range of imidazole, with a pKa of 6.95, is approximately within one pH unit above and below this value. Therefore, given the options, the correct effective buffering range is from 5.95 to 7.95. This range is based on the principle that buffers function optimally when the pH is within ±1 pH unit of the weak acid's or base's pKa value. This is due to the relationship between the titration curve and buffer effectiveness.