Read the passage and then answer the questions.

A plant cannot thrive in the wrong soil and the wrong climate. The ambitious man, however well qualified and efficient he may be, will get nowhere if he is in the wrong environment. If the business in which you are employed does not provide the openings for your initiative, does not give authority commensurate with responsibility, or lacks principle in its dealings, have the matter out with the responsible officer, and if you get no satisfaction don't be afraid to look elsewhere for a job. You can think too much of the security of your present job and not enough of going out and getting and doing something far better. Don't be seduced by the lure of the 'rut'. Ambition is a worthy characteristic, and wisely directed can spur a man on to do the best of which he is capable.
The list of factors making for happiness is quite short. A list of the factors determining unhappiness would be much longer. What you dislike and fear seems to be just waiting for you, and what you seek and desire seems to be most evasive - and when you find it at last it may easily be not exactly flawless. Happiness, both temporary or permanent, is an exceedingly subjective and individual phenomenon for which there can be no completely reliable rules. A philosophic point of view, capable of coping successfully with the vicissitudes of life, is a great asset.
H. R. Light, The Business Executive

(a) Explain the meaning of the following expressions:
commensurate the lure of the 'rut'
subjective vicissitudes.

(b) List in your own words, the features of a business which may provide the wrong environment for an ambitious man.

(c) Rewrite in your own words the sentence 'Happiness ... reliable rules.'