What is the estimated 95% confidence interval (CI) of the average difference in blood vitamin D levels between short sleeve shirt and tank top attire amongst US landscapers in ng/mL?

Subject	Time Point 1, Shirts	Time Point 2, Tank Tops
Vitamin D (ng/mL)	Vitamin D (ng/mL)
1	47.982	43.994
2	50.218	47.527
3	47.244	46.705
4	50.756	51.324
5	39.696	53.771
6	48.27	43.244
7	47.474	47.28
8	46.347	49.09
9	35.603	42.009
10	51.295	50.699
11	45.76	42.598
12	43.728	60.732
13	55.039	54.366
14	41.082	49.838
15	44.923	50.694
16	39.795	51.985
17	45.408	59.082
18	41.21	45.009
19	43.985	47.012
20	57.753	46.804
21	50.208	43.766
22	44.732	58.821
23	45.859	46.783
24	46.38	51.465
25	39.006	54.809
26	46.692	47.432
27	52.745	40.015
28	46.431	42.791
29	44.759	50.62
30	53.389	44.779
31	44.53	47.658
32	45.558	59.7
33	46.415	45.107
34	48.328	61.352
35	52.945	40.832
36	44.715	49.601
37	44.06	49.304
38	46.583	50.88
39	43.754	47.979
40	50.544	46.568
41	51.865	45.679
42	45.976	55.805

choices:

a. 0.18 to 4.89 ng/mL

b. 0.17 to 5.23 ng/mL

c. 0.15 to 4.42 ng/mL

d. 0.17 to 5.67 ng/mL