1. Change x = 4t into x = 3t
[tex]4t\cdot\frac{3}{4}=3t[/tex] so
[tex]y=(\frac{3}{4}t)^2-1=\frac{9}{16}t^2-1[/tex]
Answer A and D are wrong.
2. Change x = 4t into x = 2t
[tex]4t\cdot\frac{1}{2}=2t[/tex] and
[tex]y=(\frac{1}{2}t)^2-1=\frac{t^2}{4}-1[/tex]
Answer b is correct.
3. Change x = 4t into x = 8t
[tex]4t\cdot2=8t[/tex] and
[tex]y=(2t)^2-1=4t^2-1[/tex]
Answer C. is correct, E. is wrong.