Critical Reasoning

-Two years ago, the cost of the raw material used in a particular product doubled after an
earthquake disrupted production in the region where the material is mined. Since that time,
the company that makes the product has seen its profit margins decline steadily. Aiming to
improve profit margins, the company's head of engineering has decided that he must find a
new source for the raw material. Which of the following, if true, would cast the most doubt
on the validity of the head of engineering's decision?
A) New competitors have entered the market every six months for the past two years, resulting
in price wars that have progressively driven down revenues across the market.
b) Although the earthquake occurred two years ago, the region's mines have still not recovered
to pre-earthquake production capacity.
c) There are several other regions in the world where the raw material is mined, but those
regions do not produce as much of the raw material as the current source region.
d) The company could use a completely different raw material to make its product.
e) Recent advances in mining technology will make mining the raw material much more
efficient and cost-effective in the future.

Plz explain how you have come up with answer...It would help if u can discuss more on strategy rather than just saying the answer....Thank you....

Cost of raw material doubled post earthquake as production is disrupted -> Profits decline ->
New source -> To improve profits as the head assumes the above two are linked.

A.Provides alternate cause for the profits to decline. So manager's decision is weakened.
B.Will weaken if it stated about when it will be back to normal to improve the conditions.
C.A contender but isn't good compared to option A.
D.Supports the argument
E.Irrelevant.

IMO A.

-Two years ago, the cost of the raw material used in a particular product doubled after an
earthquake disrupted production in the region where the material is mined. Since that time,
the company that makes the product has seen its profit margins decline steadily. Aiming to
improve profit margins, the company's head of engineering has decided that he must find a
new source for the raw material. Which of the following, if true, would cast the most doubt
on the validity of the head of engineering's decision?

A) New competitors have entered the market every six months for the past two years, resulting
in price wars that have progressively driven down revenues across the market. This means even if the head of Engg. finds a different source of raw material, it is not necessary that he'll be able to improve his margins! A strong contender!!
b) Although the earthquake occurred two years ago, the region's mines have still not recovered
to pre-earthquake production capacity. this point talks only about the region, may be there are various other regions in the world! does not weaken!!
c) There are several other regions in the world where the raw material is mined, but those
regions do not produce as much of the raw material as the current source region. so what?? even the quantity mined in other area's may be more than enough to suffice the worlds need of the raw material!! does not weaken!!
d) The company could use a completely different raw material to make its product. I'll say even this is a contender, i.e. the point made here is head of Engg does not need to look for a diff source of material, there is an alternative raw material available!! kind of 'weakens'
e) Recent advances in mining technology will make mining the raw material much more
efficient and cost-effective in the future.absolutely, out of scope!!

Will go with A!!