Read the passage and answer the questions that follow.
The Day of the Triffids
By John Wyndham
The Triffids provided me with a job that comfortably supported me. They also on several occasions almost took my life. On the other hand, I have to admit that they preserved it, too, for it was a Triffid sting that landed me in the hospital on the critical occasion of the 'comet debris'.
In the books there is quite a lot of loose speculation on the sudden occurrence of the Triffids. Most of it is nonsense. Certainly they were not spontaneously generated as many simple souls believed. Nor did most people endorse the theory that they were a kind of sample visitation - harbingers of worse to come if the world did not mend its ways and behave its troublesome self. Nor did their seeds float to us through space as specimens of the horrid forms life might assume upon other, less favoured worlds - at least, I am satisfied that they did not.
I learned more about it than most people because Triffids were my job, and the firm I worked for was intimately, if not very gracefully, concerned in their public appearance. Nevertheless, their true origin still remains obscure. My own belief, for what it is worth, is that they were the outcome of a series of ingenious biological meddling - and very likely accidental at that. Had they been evolved anywhere but in the region they were, we should doubtless have had a well documented ancestry for them. As it was, no authoritative statement was ever published by those who must have been best qualified to know.
According to the author, ______________.
AWithout doubt, we have detailed accounts of the ancestry of the Triffids
BComprehensive records of the origin of the Triffids aren’t available
CThe region in which the Triffids originated is well-documented
DNo one was qualified to publish a reliable account of the Triffids’ ancestry
answer should be B. It is clearly mentioned in last paragraph,''Nevertheless, their true origin still remains obscure''.