Order of least Margin of error in the graph given below is?

(a) 3>2>1,Ref: Biostatistics Principles and Practice by B. Antonisamy and Me grow hill publication, pg. 44-45Given image shows three normal distribution curve of different sample size.All three curves have same mean but different standard deviation. As the sample size is decreasing, flatness of curve increasing and peak of curve diminishing which signifies wider confidence interval for given mean.Narrower the base of curve, lesser the margin of error will be.In given question, curve 1 has least margin of error followed by curve 2 and curve 3 shows highest margin of error. Hence correct answer is 3>2>1.