Answer:
C. John K. Daniels.
Explanation:
Looking at the timeline of the "Butter Artists of the Iowa State Fair", we can see that John K. Daniels started in 1911 followed by J. E. Wallace in 1913. Then, in 1957, Earl Frank Dutt took over followed by Norma Lyon in 1960. And last among them is Sarah Pratt who started in 2006.
So, according to the active years of their 'service', the shortest duration of work as the state artist is John K. Daniels who got replaced by J. E. Wallace in 1913. He worked for just 2 years while the others worked for more than 3 or more years.
Thus, the correct answer is option C.