Write an Equivalent Double Integral with the Order of Integration $\int _ { 0 } ^ { 3 } \int _ { 0 } ^ { 7 y / 3 } d x d y$

Multiple Choice

Write an equivalent double integral with the order of integration reversed.
- $\int _ { 0 } ^ { 3 } \int _ { 0 } ^ { 7 y / 3 } d x d y$

A) $\int _ { 0 } ^ { x } \int _ { 0 } ^ { 3 / 7 } d y d x$
B) $\int _ { 0 } ^ { 7 } \int _ { 3 x / 7 } ^ { 3 } d y d x$
C) $\int _ { 0 } ^ { 7 } \int _ { 0 } ^ { x / 3 } d y d x$
D) $\int _ { 0 } ^ { 7 } \int _ { 0 } ^ { 7 x / 3 } d y d x$