Final answer:
Environmental liabilities that cannot be reasonably estimated need not be disclosed in the financial statements or related notes. Probable losses not reasonably estimable and guarantees of indebtedness of others must be disclosed, as their existence can significantly influence financial decisions.
Step-by-step explanation:
The student's question pertains to the disclosure of contingencies in financial statements. According to financial reporting standards, organizations are required to disclose certain types of contingencies to ensure transparency and provide an accurate picture of their financial position. However, certain contingencies may not require disclosure depending on their nature and the ability to estimate them.
Environmental liabilities that cannot be reasonably estimated need not be disclosed because there is not enough information to provide a useful or accurate disclosure. Conversely, probable losses that are not reasonably estimable and guarantees of indebtedness of others do need to be disclosed, even if the specific amounts are not able to be precisely determined. This is because the mere existence of these contingencies can be material enough to influence the decision-making of users of the financial statements.
In conclusion, of the given options, environmental liabilities that cannot be reasonably estimated need not be disclosed in the financial statements or the related notes, provided they cannot be estimated with sufficient precision. It is the responsibility of the organization to assess and make this determination based on the relevant financial reporting guidelines.