LV fones co.- fee dependency

maam in secion A specifically if the question does not mention whether the client is listed to not then we have to assume that it is not listed?

You are an audit manager in CL & Co, an accountancy firm with six offices and 15 partners.
You are planning the audit of LV Fones Co, which has been an audit client for four years and specialises in manufacturing luxury mobile phones. During the planning stage of the audit you have obtained the following information.
The audit team of LV Fones Co are entitled to purchase mobile phone accessories at a discount of 10%. The finance director has commented that this is to encourage the audit team to be more favourable towards the company and to keep them on side. The audit engagement partner has assessed the potential value of the discount to be trivial and inconsequential to any individuals who wish to take advantage of this offer.
During the year, the financial controller of LV Fones Co was ill and hence unable to work. The company had no spare staff able to fulfil the role and hence a qualified audit senior of CL & Co was seconded to the client for three months. The fee income derived from LV Fones Co was boosted by this engagement and along with the audit and tax fee, now accounts for 16% of the firm’s total fees.

Which of the following actions should CL & Co take to maintain their objectivity in relation to the level of fee income from LV Fones Co?

Perform an independent review of the work
Increase the client base
Disclose the issue to the audit committee
Resign if fees exceed 15% of the firm’s total income for two consecutive years

here the answer is option numbers 1 and 2.

explanation states that because LV fines is a non-listed co., option 3 and 4 would be for listed co. however there is absolutely no mention whether the company is listed to not. So how do we know?