Blind Valley is found in
Okay, so here is the simple version. Blind Valley is found in points to Karst Region. In Valleys, this is taught as a basic fact. You do not need a long story for it. Just remember the connection and move on. It will come back to you in the exam.
Ref: [UP UDA/LDA (Pre) 2013] | NCERT Geography textbooks and Goh Cheng Leong, Certificate Physical and Human Geography, discuss Valleys and explain the geographical concepts and processes that support the correct answer for this question.