[单项选择]

In the absence of optimism, we are left with nothing but critics, naysayers, and prophets of doom. When a nation expects the worst from its people and institutions, and its experts focus exclusively on faults, hope dies. Too many people spend too much tie looking down rather than up, finding fault with their country’s political institutions, economic system, edncational establishment, religious organizations, and—worst of all—with each other.
Faultfinding expends so much negative energy that nothing is left over for positive action. It takes courage and strength to solve the genuine problems that afflict every society. Sure, there well always be things that need fixing. But the question is, Do you want to spend your time and energy tearing things down or building them up
The staging of a Broadway show could illustrate my point. Let’s say a new production is about to open. A playwright has polished the script, investor have put up the money,
A. explain that staging a play requires complex teamwork
B. argue that a minute mistake may ruin a lifelong task
C. show that the preparatory stage is imperative t the following ones
D. illustrate that criticism may block the way to success