It depends on what you are referring to.
If you are talking about the company itself, for example, when it was founded, you will say <em>it - </em>It was founded in 1993.
However, if you are talking about its employees, then you should use <em>they.</em>
After the season was on air, things were not right between Hannah Ann and Peter and they stopped dating.
<u>Explanation:</u>
Till the sixth of January before the premier of the season was done, Hannah Ann confirmed that she was dating Peter and both of them were together till that date.
But after the season started coming on air and was broadcasted which was the early time in the month of January itself, Hannah Ann herself confirmed that the things were not going too well between the couple and they were facing some problems in the relationship.
I would have actually written it this way
"Hellen arrived unannounced when the house was a mess, and we weren't ready for visitors."
But, I guess, the closest answer to this one would be the last option. :)
Hope this helps.
The study of the structure an behaviour of the physical and natural environment by oberseving through scientficic instruments and through experiments.
