This task is about creating an unanswerable question based on a given passage. Construct a question that looks relevant to the given context but is unanswerable. Following are a few suggestions about how to create unanswerable questions:
(i) create questions which require satisfying a constraint that is not mentioned in the passage
(ii) create questions which require information beyond what is provided in the passage in order to answer
(iii) replace an existing entity, number, date mentioned in the passage with other entity, number, date and use it in the question
(iv) create a question which is answerable from the passage and then replace one or two words by their antonyms or insert/remove negation words to make it unanswerable.

Ex Input:
Passage: The noise-based speed is defined as the exposure that will lead to a given signal-to-noise ratio on individual pixels. Two ratios are used, the 40:1 ("excellent image quality") and the 10:1 ("acceptable image quality") ratio. These ratios have been subjectively determined based on a resolution of 70 pixels per cm (178 DPI) when viewed at 25 cm (9.8 inch) distance. The signal-to-noise ratio is defined as the standard deviation of a weighted average of the luminance and color of individual pixels. The noise-based speed is mostly determined by the properties of the sensor and somewhat affected by the noise in the electronic gain and AD converter.

Ex Output:
Which ratio was subjectively determined?

Ex Input:
Passage: Literature allows readers to access intimate emotional aspects of a person's character that would not be obvious otherwise. It benefits the psychological development and understanding of the reader. For example, it allows a person to access emotional states from which the person has distanced himself or herself. An entry written by D. Mitchell featured in ''The English Journal'' explains how the author utilized young adult literature in order to re-experience the emotional psychology she experienced as a child which she describes as a state of "wonder".

Ex Output:
What gives readers access to physical aspects of a character?

Ex Input:
Passage: Several campus safety strategies have been pioneered at Yale. The first campus police force was founded at Yale in 1894, when the university contracted city police officers to exclusively cover the campus. Later hired by the university, the officers were originally brought in to quell unrest between students and city residents and curb destructive student behavior. In addition to the Yale Police Department, a variety of safety services are available including blue phones, a safety escort, and 24-hour shuttle service.

Ex Output:
When were the last campus police formed at Yale?