A number of sentences are given below which, when properly sequenced, form a coherent paragraph. Each sentence is labelled with a letter. Choose the most appropriate and logical order of sentences and answer the questions that follows:
A- They have even succeeded in heart transplants.
B- All this was made possible by the invention of the heart lung machine.
C- Now-a-days surgeons are able to stop a patient’s heart and carry-out complicated operations.
D- If the heart stops working, we die in about five minutes.
E- The heart is the pump of life.
F- A few years ago, it was impossible to operate on a patient whose heart was not working properly.
Which of the following will be the fourth sentence?