In the following passage some words have been deleted. Read the passage carefully and select the most appropriate option to fill in each blank.
Sustainability is ____ (1) ____ longer just a buzzword. It ____ (2) ____ a necessity and the primary agenda of the world today. Like many other countries, India too is witnessing a growth of ____ (3)____ green economy. It ____ (4)____ estimated that India's renewable energy target will create more than 3.4 million new job opportunities ____ (5)____ 2030. In fact, a recent survey stated that a Sustainability Manager is going to be one of the top 10 jobs this decade.

In the context of the passage, select the most appropriate option to fill in blank (4).

1. A
   will be
2. B
   were
3. C
   had been
4. D
   is