I need help with these two problems please and please answer all parts and please make it legible. I've been having a lot of problems with the tutors today.

Find the curve's unit tangent vector. Also, find the length of the indicated portion of the curve. r(t) = (7cost)i + (7sint)j + (17t)k, Osts= . . . . . Choose the correct answer for the unit tangent vector of r(t). O A. T(t) = 14 sint)i- (Via cost)1+ (12 ) x O B. T(t) = V14 4 - sint i+ V14 cost 1+ V2 O c. T(t) = ~14 sint : - (V14 cost) 1 + (12]k O D. T(t) = Via sintJit ( Via cost)It ( 12 )KFind the curve's unit tangent vector. Also, nd the length of the indicated portion of the curve. r(t)=5ti+[]t3'2k, Osts11 Next question The curve's unit Engent vector is ( i + i+( (Type exact answers, using radicals as needed.)